Experimental Drug Cut Muscle Loss During Weight Loss

A study found a new medication helped preserve lean muscle in adults using semaglutide to lose weight.

Updated on Sept. 30, 2026 in Weight Loss

Isometric editorial illustration of abstract, sculptural muscle fiber structures in muted oxblood, teal, and mustard tones. — Regeneron's experimental drug trevogrumab successfully reduced lean muscle mass loss by 50% in patients using semaglutide for weight loss, researchers reported in Milan. AI Illustration. Upload story photo >

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Would you prioritize taking a weight-loss drug that specifically preserves muscle mass over other options?

Regeneron's experimental drug trevogrumab reduced lean muscle mass loss by 50% in patients also taking semaglutide. The finding, presented recently at a medical conference in Milan, offers a potential strategy for improving the quality of weight reduction.

Why it matters

Preserving muscle mass during medical weight loss is critical for maintaining metabolism and functional strength. This research aims to address the common clinical concern that weight-loss therapies can cause significant loss of lean tissue alongside body fat.

In a clinical trial of nearly 1,000 patients, those receiving a 75-mg dose of trevogrumab alongside semaglutide experienced a 3.3% loss of lean muscle mass, compared to a 6.7% loss among those taking semaglutide alone over 26 weeks. Researchers confirmed these findings using MRI scans to measure changes in thigh muscle mass.

The players

Regeneron

A biotechnology company focused on developing pharmaceutical treatments for various diseases.

The details

Trevogrumab works by inhibiting myostatin, a protein that naturally limits muscle growth and maintenance in the human body. By blocking this protein, the drug aims to counteract the muscle-wasting effects often observed during rapid weight reduction. While the trial showed promise for muscle preservation, Regeneron discontinued a separate high-dose combination trial involving garetosmab after two participant deaths were reported.

26 weeks was the duration for the initial muscle mass loss measurement.
52 weeks is the period tracked for 75mg trevogrumab muscle preservation.
Thursday, September 24, 2026, was when the data was presented in Milan.
2035 is the year analysts project potential annual sales for these therapies.

Health Landscape

This research reflects a growing shift in the obesity treatment landscape, moving from simple weight reduction toward managing body composition. It follows a pattern set by the development of GLP-1 receptor agonists, aiming to address the metabolic trade-offs associated with these potent weight-loss drugs.

If you are currently managing your weight under medical supervision, it is worth discussing the potential risks and benefits of muscle-sparing approaches with your physician. This study is preliminary, and you should remain informed about clinical trial developments that may eventually impact future care standards.

The takeaway

Maintaining muscle health is as important as fat loss for long-term metabolic function. Always monitor your physical strength and body composition changes while on a weight-loss plan and consult your doctor about any concerns regarding lean mass preservation.